In 1966 ninety-one hybrid plum seeds were created from controlled pollinations between `Valor` .times. `Iroquois`. A population of seedlings with the New York State Agricultural Experiment Station breeding record designation NY 66.609 were planted in 1967 in an orchard designated as Crittenden 30 in Row 7 Trees #124 through #215. One seedling in this population was planted at Cr30R7T#165. In 1972 it fruited for the first time and in 1974 it was selected for further testing because of its early ripening season and its high quality and interesting dark purple colored fruit. It was designated NY 66.609.4 and grafted in 1974 at the New York State Agricultural Experiment Station, Geneva, N.Y. 14456 to Myrobolan,` a seedling plum rootstock, utilizing the nursery t-budding grafting technique. These grafts produced trees to be used for more tests of this selection's merit. Grafted trees that resulted were planted in 1976 in a Station field designated as Crittenden 22R10T1, T2 and Cr22R13T19, T20, T21. In 1983 further grafted trees resulted from using buds taken from Cr30R7T165 for propagating wood and subsequently these grafted nursery trees were planted at Cr23 R5T27. T28, T29. In the ensuing years third clonal generation trees were created utilizing buds for propagating wood taken from the Cr22R10 and Cr22R13 trees. Such third generation trees were distributed under redistricted, nondistribution test agreements to collaborators in the USA and Canada who assisted us in evaluating the merit of this selection.
NY 66.609.4 is being named and released as `Castleton` and is the subject of this invention.